The invention relates to conduits for conveying fluids of the type having an inner conduit disposed within an outer conduit, and to methods and systems employing such conduits. The invention further relates to processes and systems employing such conduits to convey hydrocarbon mixtures or other fluids or gases.
In subsea hydrocarbon production systems, it is common practice to adopt a field architecture that utilizes dual production lines in a loop configuration connecting subsea equipment to a host facility. This looped configuration has proven to be effective in fulfilling several important objectives in a commercial subsea hydrocarbon production operation such as flow assurance, operating flexibility and reliability. Such systems also require means of maintaining steady state production, and mitigating critical operational situations such as emergency and planned shut downs, start ups and blockages to flow in production lines that may hinder or cease production. Systems are needed which prevent or correct blockage by hydrates or other solids within production lines. Several existing methodologies and technologies are utilized to maintain flow in production lines, including, but not limited to, the following: thermal insulation, heating, pigging, artificial or gas lift, displacement of production fluids, chemicals, coiled tubing intervention into production lines, circulation of hot fluids, de-pressurization of production lines and well testing.
There remains a need for new solutions which reduce the complexity of subsea and onshore hydrocarbon production systems, while providing for more operational flexibility, to allow a broader range of operational alternatives in order to deal with planned and unplanned flow disruption scenarios to maximize production uptime and product recovery.